Quality and Yield of Vaccinia Virus from L Cell Cultures.

Abstract
Summary The first vaccinia virus particles produced in cultures of L cells are low in quality; poor in plaque forming ability. The quality of the total virus product of these cultures improves rapidly at first, then more slowly throughout the 90-hour incubation period. Electron micrographs have not shown clear distinguishing morphological features of the early virus such as those of incomplete influenza virus. Growth curves of vaccinia virus particles in our cultures are single phase. They rise abruptly and approach a maximum in the manner of a chemical reaction which is limited by shortage of one reactant.